Machine to machine (M2M) is a concept encompassing devices, such as for instance sensors and so-called smart devices, using a network for communicating with remote applications of e.g. a server of Internet. Such communication may for instance be for the purpose of monitoring and control. Internet of Things (IoT) refers to a network of objects (“things”) with network connectivity, and M2M may be considered an integral part of IoT. Together M2M/IoT covers a huge set of devices that communicate with each other directly and across networks based on various communication or access media, using short range technologies (e.g. Bluetooth or WiFi) as well as long range technologies (e.g. radio access such as 3G or 4G).
LightweightM2M (LWM2M) is a new standard from the Open Mobile Alliance (OMA) that is focused on constrained cellular devices and other M2M devices. The standard defines an efficient device-server interface based on open Internet Engineering Task Force (IETF) standards, i.e. Constrained Application Protocol (CoAP) and Datagram Transport Layer Security (DTLS). The LWM2M enabler includes device management and service enablement for LWM2M devices, and uses a light and compact protocol as well as an efficient resource data model to fit on constrained LWM2M devices.
When a new LWM2M client requests to register to the network, a DTLS connection may be established between the LWM2M client and the bootstrap server, after which a bootstrapping procedure is performed. In the bootstrapping procedure the LWM2M client is configured with required parameters such as security credentials, e.g. private keys, certificates or pre-shared key. Next, the LWM2M client establishes a DTLS connection with the LWM2M server and is then registered to the network and ready to e.g. report measurement values.
LWM2M clients typically have limited processing and storage capabilities and also a limited or very limited power source. The power consumption of the LWM2M client is hence an issue and needs to be considered so as to keep the device functional as long as possible without maintenance. In view of this, there is a need to make the LWM2M client registration to the network as efficient as possible.